For traffic and transport companies like railway, bus, airline and transport companies, it is necessary for the companies to decide exactly how to use crews who are to be on duty on vehicles. In case of a railway, for example, a prescription prescribing, which driver should drive which train, or a certain driver should next drive which train after he has driven some train and arrived at a terminal is called a crew roster. When producing such a crew roster, it should be considered that crews of a limited number fully but not excessively work, keeping to fixed working regulations, with the consideration of rolling stocks, railway districts and the like which the driver can drive, corresponding to a fixed train diagram.
The production work of crew rosters can be roughly divided into following two works:
The first work is to produce a crew itinerary by combining several of multiple train diagrams. The "crew itinerary", usually called simply "itinerary", is a path which a crew follows from departure at his train district to arrival at the same district (occasionally, after lodging). The first work will be described sequentially as follows: On the basis of a train diagram which determines that some train departs from some station at a certain time and arrives at some station at a certain time, a rolling stock operation diagram is produced which determines which rolling stocks should be allotted to the train diagram. The rolling stock operation diagram is fragmented at, for example, change stations where the crew changes the train, to produce many itinerary units (also called roster lines). These itinerary units are combined to make an itinerary. A diagrammatized itinerary is a crew roster diagram.
The second work is to produce a group duty schedule at a designated train district, based on the multiple itineraries thus produced. This procedure is called the group duty schedule production work or group schedule production work. The group schedule is a schedule which is produced by combining all duty schedules for crews of one group in one working unit, while several crew members are united to one group. Therefore, a crew belonging to the same group works according to the schedule, shifting it by one day work. A group schedule is produced by properly combining multiple itineraries. When producing it, it is considered that conditions such as labor hours, number of overnight shift, meal time and the like become equal for each crew and the working regulations are not violated. When a case occurs where such conditions do not become equal or the working regulations are violated, the first work is carried out again and the second work is redone after itineraries are replaced.
Since such crew roster production works were all done manually, much time and labor were needed. Therefore, machines for assisting the production works have been developed. Among them, as a machine for assisting the first work, for example, Japan Patent Laid-open Hei 5-298593 is known. According to the publication, diagram fragments produced from data of a rolling stock operation diagram are combined to form a group that is a higher element, considering, for example, stations where crews can be changed or the like as the restrictive conditions. The groups are combined to produce crew itineraries. Since crew rosters are produced by combining groups that are higher elements, the total number of combination in the production of crew itineraries is decreased compared with a case where each diagram fragment is combined and therefore, the load on the operator is decreased.
However, according to a machine shown in Japan Patent Laid-open Hei 5-298593, since the crew itinerary production was carried out from quite a blank sheet, the total number of combination for producing the crew itineraries still became so huge that the machine could not be used in practice, even if several diagram fragments produced from data of a rolling stock operation diagram were combined to form a group and such groups were combined to produce crew itineraries.
The invention is presented in respect of the aforementioned problem and the purpose of the invention is to provide a machine for assisting crew itinerary production which makes it possible to efficiently produce practical crew itineraries within a short period of time, with a decrease of the operator's burden.